Forces Flashcards

1
Q

What do scalar quantities have

A

Magnitude only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do vector quantities have

A

Magnitude and an associated direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How can the vector quantity be represented

A

As an arrow.

the length of the arrow=magnitude
the direction of the arrow=direction of the vector quantity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Force

A

A push and pull that acts on an object due to the interaction with another object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are all forces between objects due to

A

Contact forces - the object are physically touching
Non-contact forces - the objects are physically separated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What type of quantity is force

A

Vector quantity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give examples of contact forces

A

Friction
air resistance
tension
normal contact force 

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give examples of noncontact forces

A

Gravitational force
electrostatic force
magnetic force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the force of gravity due to

A

The gravitational field all around the Earth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the weight of an object depend on

A

The gravitational field strength at the point where the object is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the weight of an object on the mass of an object

A

Directly proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is weight measured

A

Using a calibrated spring balance ( a Newton meter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the single force called

A

The resultant force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does magnitude mean

A

Size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The weight of an object is directly proportional to the mass what does this mean

A

If we double the mass the weight will double

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The weight of an object may be considered to act at a single point what is this called

A

The center of mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Weight is the force acting on an object what is this due to

A

Gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What might the number of forces acting on an object be replaced by

A

A single force that has the same effect as the original forces acting together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What can a single force be resolved into

A

Two components acting at right angles to each other
(the two components force work together have the same affect as the single force(Single force=resultant force))

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

If the forces are balanced what does it mean

A

The resultant force is zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When a force causes an object to move through a distance what does this mean

A

Work is done on the object

So a force does work on an object when the force causes a displacement of the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does work done against the friction forces acting on an object cause 

A

It causes a rise in the temperature of the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

1 joule = ? Newton-meter

A

1 Newton meter

1 joule of work done when a force of one Newton causes a displacement of 1 m

25
What will happen to elastic materials if we take away the force acting on them
It will return back to the original length or shape
26
What is an elastic deformation and inelastic deformation
Elastic returns to its original shape after force has been applied Inelastic doesn’t return back to its shape after force has been applied
27
Required practical: describe how to investigate the relationship between force and extension for a spring
..
28
What does linear mean
Straight line
29
What is distance
How far an object moves. distance does not involve direction meaning it’s a scalar quantity
30
What is displacement
Both the distance an object moves measured in a straight line from the start to the finishing points in the direction of the straight line meaning displacement is a vector quantity
31
What does speed not involve
Direction meaning speed is a scalar quantity
32
What does the speed of a person depend on
Age, fitness and distance traveled
33
What’s the speed of a person walking running and cycling
Walking 1.5 m/s running 3 m/s cycling 6 m/s
34
What is the typical value of speed of sound in air
330 m/s
35
What’s the speed of the car on the main road, a fast train in UK and a cruising aeroplane 
Car on the main road 13 m/s fast train in the UK 50 m/s cruising aeroplane 250 m/s
36
What is velocity
The velocity of an object is its speed in a given direction meaning it’s a vector quantity
37
What changes in a circular motion that involves a constant speed
The velocity keeps changing
38
An object that slows down is called
Deceleration
39
When any objects falls towards the surface of earth it accelerates around what
9.8 m/s squared
40
When the object stops accelerating and moves at a constant velocity what is this called
Terminal velocity
41
What happens to an object falling through a fluid
It’s accelerates due to the force of gravity eventually the resultant force will be zero and the object will move at its terminal velocity
42
The velocity of an object will only change when
A resultant force is acting on the object
43
What is newtons first law of motion
If the object is stationary it will remain stationary If the object is moving it will continue to move at the same speed and in the same direction so the object continues to move at the same velocity
44
What is balanced when a vehicle travels at a steady speed
The resistance forces they including friction with the air and friction with the road 
45
What is the Object that stays stationary or continues moving at the same speed and direction unless a resultant force is applied called
Inertia
46
What is newtons second law
The acceleration of an object is proportional to the resultant force acting on the object and inversely proportional to the mass of the object
47
What is newtons third law
Whenever to objects interact the forces are exerted on each other are equal and opposite
48
What is the stopping distance of a vehicle
The sum of the distance the vehicle travels during the drivers reaction time and the distance it travels under the breaking force for a given breaking force the greater (the speed of the vehicle the greater the stopping distance)
49
What is the typical value of the reaction time from person to person
0.2 to 0.9 seconds
50
What can the drivers reaction time be affected by
Tiredness drugs alcohol distractions may also affect the drivers ability to react
51
What is the braking distance of a vehicle affected by
The road the weather conditions the poor condition of the vehicle
52
What is the inertial mass
A measure of how difficult it is to change the velocity of an object (It’s defined as: the ratio of force/acceleration)
53
What type of road conditions cause the braking distance of vehicle to change
Icy or wet conditions And for the car it’s limited to the brakes or tyres
54
Required practical: How to investigate the mass and force affects acceleration
Set of a toy car that is attached to a string and the string is looped around a pulley that is attached to a 100g mass The weight of the mass will provide a force acting on the toy car Do you need a timer and using chalk drawing lines at equal lengths Hold the toy car at the starting point and let go of the car Because there is a force with the string the car will accelerate along the bench Records the time that the car passes each distance You could record the experiment on her mobile phone and play the video back to records accurate times Then repeat the experiment but decrease the mass on the end of the string The object is the toy car the string and the mass attached to the string all as 1
55
What happens when force is applied to the break of the vehicles
Work is done by friction force between the brakes on the wheels reduces the kinetic energy of the vehicle and the temperature of the brakes increases
56
Degree to the breaking force what happens to the deceleration
The deceleration of the vehicle is greater larger decelerations may lead to the brakes overheating or loss of control
57
What happens to the momentum in a close system
The total momentum before an event is equal to the total momentum after the event
58
What is conversion of momentum
In a close system the total momentum before and after is equal